JPH082945Y2 - Coaxial tube connection - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial field of application] The present invention relates to a connecting portion of a coaxial tube used as a power supply line for broadcasting and the like, and particularly to a connecting portion of a coaxial tube having improved reliability.

[Conventional technology]

As a conventional connecting portion of a coaxial tube, there is one shown in FIG. 7, for example. That is, the connection terminal 1 has a plurality of slits 2a.
The fitting portion 2 having the is attached to the tip end portion in the axial direction, and the fitting portion 2 is inserted into the hollow portion of the central conductor 3 so as to be electrically connected. In this way, the fitting part 2
Since a plurality of slits 2a are formed in the fitting portion 2
Can be elastically engaged with the hollow portion of the central conductor 3.

However, according to the connecting portion of the coaxial tube, since the engagement between the central conductor and the fitting portion is performed by the spring action of the plurality of slits, the elastic force is reduced due to long-term use. Therefore, there is an inconvenience that the contact resistance between the fitting portion and the center conductor increases, which increases the electrical resistance and causes abnormal heat generation in the connection portion. Further, when the coaxial tube is used, the fitting portion and the center conductor slide due to thermal expansion and contraction, and the fitting portion or the center conductor is worn and metal powder is generated. This may cause a decrease in withstand voltage and may cause a short circuit accident or the like.

To prevent this, for example, there is a coaxial cable connection terminal disclosed in Japanese Utility Model Publication No. 57-38866. This connection terminal has a hollow portion at the tip, and inserts a compression spring into it, and the extension force of this compression spring is received by a stopper arranged at the tip of the hollow portion, and the elastic force received by the stopper is applied to the inner wall of the tip of the hollow portion. It is configured to be received by the tapered protrusion formed on the. Therefore, when the tapered protrusion receives an elastic force, it is urged so that the outer diameter of the terminal end having the hollow portion expands, and as a result, it stays with the center conductor of the coaxial cable for a long period of time. A good contact state is obtained.

[Problems to be solved by the device]

However, according to the latter connection terminal, since the hollow portion having the tapered protrusion is formed at the tip of the connection terminal,
Manufacturing becomes difficult, and since a compression spring and a stopper are required, the number of parts increases and the configuration becomes complicated.

Therefore, an object of the present invention is to provide a connecting portion of a coaxial tube which can maintain a good engagement state between the fitting portion and the central conductor for a long period of time.

Another object of the present invention is to provide a connecting portion of a coaxial tube which is easy to manufacture and has a reduced number of parts and a simplified structure.

[Means for solving the problem]

In order to achieve the above-mentioned object, the present invention provides a coaxial-tube connecting portion in which an annular concave portion is formed at a predetermined outer peripheral position of a fitting portion of a connecting terminal, and a cylindrical contact piece is arranged in the concave portion. It is a thing.

That is, according to the present invention, in the connecting portion of the coaxial tube connected to the hollow portion of the central conductor by inserting the tip fitting portion of the connection terminal through the contact piece, the tip fitting portion is connected to the inner diameter of the hollow portion. The outer diameter is formed by a radially extending wall that is formed between the front and rear close fitting portions that are close to the inner peripheral surface of the hollow portion by having a matching outer diameter and the front and rear close fitting portions. Has an annular recess formed to have a smaller outer diameter, the contact piece is housed in the recess and elastically contacts the inner peripheral surface of the hollow portion, and a plurality of slits are formed. The outer diameter of the apex is larger than the inner diameter of the hollow portion, the elastic cylindrical portion is formed in an arcuate shape, the inner diameter is equal to the outer diameter of the recess, and the thickness is smaller than the height of the wall of the recess. , Ring-shaped ends integrally formed on both sides of the elastic tubular portion If, to provide connection portions of the coaxial waveguide, wherein the elastic cylindrical portion, and that it is composed of split in the axial direction is continuously formed over the ring-shaped end.

〔Example〕

 Hereinafter, the connection part of the coaxial tube of the present invention will be described in detail.

FIG. 1 shows an embodiment of the present invention, in which a fitting portion 2 is provided at the tip of the connection terminal 1, and the fitting portion 2 is an outer member that fits the inner diameter of the hollow portion 3a of the center conductor 3 described later. The front and rear close-fitting portions 2b and 2c, which have a diameter and thus closely contact with the inner peripheral surface of the hollow portion 3a, and the annular concave portion 4 formed between the front and rear close-fitting portions 2b and 2c. Have A cylindrical contact piece 5 formed of beryllium copper and further heat-treated is fitted on the outer periphery of the recess 4, and the contact piece 5 has a predetermined elastic force by forming its cylindrical portion into an enormous shape. have. Therefore, the connection terminal 1 is connected to the hollow portion 3a of the central conductor 3.
, The contact piece 5 is compressed by the hollow portion 3a of the central conductor 3 and thereby gives a predetermined elastic repulsive force to the hollow portion 3a of the central conductor 3, so that the central conductor 3 and the connecting terminal 1 are given a predetermined force. The contact force is to be engaged. By this engagement, the connection terminal 1 and the central conductor 3 are electrically and stably connected.

2 (a) and 2 (b) show the connection terminal 1, which is a close fitting portion in front of and behind the fitting portion 2 provided at the tip of the connection terminal 1.
An annular recess 4 is cut between 2b and 2c, and a contact piece 5 as shown in FIG. 3 is fitted into this recess 4. The contact piece 5 is made of beryllium copper in a cylindrical shape and the cylindrical portion 5c is formed into an arcuately large arc shape, and then further heat-treated to have a predetermined elasticity. To be Ends 5a that engage with the recesses 4 are integrally formed on both sides of the tubular portion 5c.
The axial movement of the contact piece 5 is regulated by bringing the contact piece 5 into contact with the wall 4a. Further, a split 5b is formed in the axial direction of the contact piece 5, and when the contact piece 5 is fitted in the recess 4, it can be inserted from the tip of the fitting portion 2 by expanding the split 5b. Further, the tubular portion 5c has slits 5d, and the elasticity can be adjusted also by the number of slits 5d.

In the above structure, when the fitting portion 2 of the connection terminal 1 is inserted into the hollow portion 3a of the center conductor 3, the tubular portion 5c of the contact piece 5 located in the recess 4 of the fitting portion 2 becomes hollow in the center conductor 3. It is compressed by 3a and its elastic repulsive force is applied to the hollow portion 3a of the central conductor 3. Therefore, the center conductor 3 and the contact piece 5 are elastically engaged with each other, so that the connection terminal 1 and the center conductor 3 are electrically connected.

Next, in order to compare the connection part of the coaxial tube of the present invention with the connection part of the conventional coaxial tube shown in FIG. 7, an insertion / extraction test was conducted using the test apparatus shown in FIG. Here, the test device will be briefly described. The connection terminal 1 (including the fitting portion 2 and the contact piece 5) connected to the central conductor 3 is fixed at a predetermined position, and the central conductor 3 is a sliding device. It is attached to 6. The sliding device 6 moves the central conductor 3 in the vertical direction (arrow direction), and inserts and removes the central conductor 3 to and from the connection terminal 1. Reference numeral 7 denotes a measuring device at the time of inserting / removing the sliding device 6, which measures the pulling force or the inserting force of the sliding device 6.

FIGS. 5 and 6 are graphs showing the test results, FIG. 5 showing the connecting portion of the conventional coaxial tube, and FIG. 6 showing the connecting portion of the coaxial tube of the present invention. As you can see from the graph,
It can be seen that in the conventional type shown in FIG. 5, both the pulling force and the inserting force decrease as the number of sliding times increases. This indicates that the contact state of the connection portion, that is, the engagement between the connection terminal and the center conductor is weakened by the decrease in elastic force. Further, in the case of the present invention shown in FIG. 6, it can be seen that the number of times of sliding increases and neither the pulling force nor the inserting force decreases. That is, it indicates that the contact state between the connection terminal and the central conductor is maintained in a good state for a long period of time. As described above, according to the connecting portion of the coaxial tube of the present invention, the contact state of the connecting portion can be maintained in a good state for a long period of time, so that the reliability can be improved. In addition, in the case of accidents caused by metal powder, which is a conventional problem, since metal powder is stored in the recess (contact piece) formed in the fitting part, it is possible to prevent accidents, etc. The reliability can be further improved. In addition, in FIG. 5 and FIG.
The reason why the insertion / removal force increases at about the time of rotation is that the contact area increases as the shapes of the central conductor and the connection terminal become compatible with each other due to the engagement, and the present invention uses the increased insertion / removal force for a long time. Can be maintained.

[Effect of device]

As explained above, according to the connecting portion of the coaxial tube of the present invention, an annular concave portion is formed at a predetermined position of the fitting portion of the connection terminal, and the elastic contact piece having the enlarged portion is arranged in the concave portion,
Since the contact piece is elastically engaged with the hollow portion of the central conductor, the following effects can be obtained.

(1) The contact between the fitting portion and the center conductor can be favorably maintained over a long period of time, and the reliability of the connection portion can be improved.

(2) Since metal powder generated by the sliding of the fitting portion and the central conductor is stored in the recess formed in the fitting portion, a short circuit accident or the like can be prevented.

(3) When the contact piece deteriorates, it is not necessary to replace the entire connection terminal, and only the contact piece needs to be collected.

(4) Since the recess is formed on the outer periphery of the connection terminal, the manufacturing is easy, and since the contact piece is simply fitted therein,
The number of parts is only one, and the configuration can be simplified.

[Brief description of drawings]

FIG. 1 is an explanatory view showing an embodiment of the present invention, FIGS. 2 (a) and 2 (b) show connection terminals of the present invention, (a) is an overall perspective view, and (b) is a sectional view thereof. FIG. 3 is an explanatory view showing a contact piece of the present invention, FIG. 4 is an explanatory view showing a test device used for an insertion / extraction test, and FIGS. 5 and 6 are insertion / extraction of a connecting portion of the present invention and a conventional coaxial tube. The graph showing the result of a test, FIG. 7 is explanatory drawing which shows the connection part of the conventional coaxial tube. Explanation of symbols 1 ... Connection terminal, 2 ... Fitting part 2a ... Slit, 3 ... Central conductor 3a ... Hollow part, 4 ... Recessed part 4a ... Wall, 5 ... Contact piece 5a ... End part , 5b …… Split 5c …… Cylindrical part, 5d …… Slit 6 …… Sliding device, 7 …… Measuring device

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Creator Akira Ishii 2-2-1 Jinnan, Shibuya-ku, Tokyo Inside the Japan Broadcasting Corporation Broadcasting Center (72) Shinichi Fujiwara 2-2-1, Jinnan, Shibuya-ku, Tokyo Within the Japan Broadcasting Corporation's Broadcasting Center (56) References Showa 48-58478 (JP, U) Showa 56-120530 (JP, U) Showa 57-167576 (JP, U) Show 36- 5865 (JP, Y1) Showa 59-43652 (JP, Y2)

Claims (1)

[Scope of utility model registration request] 1. A connection portion of a coaxial tube, which is connected by inserting a tip fitting portion 2 of a connection terminal 1 into a hollow portion 3a of a central conductor 3 via a contact piece 5, wherein the tip fitting portion 2 is Front and rear close fitting parts 2b, 2c that closely contact the inner peripheral surface of the hollow part 3a by having an outer diameter that matches the inner diameter of the hollow part 3a, and the front and rear close fitting parts 2b, A wall formed between 2c and extending in the radial direction
4a has an annular recessed portion 4 formed to have an outer diameter smaller than the outer diameter, and the contact piece 5 is housed in the recessed portion 4 to form the hollow portion 3a.
The elastic cylindrical portion 5c elastically contacted with the inner peripheral surface of the apex so that the outer diameter of the apex is larger than the inner diameter of the hollow portion 3a by forming the plurality of slits 5d, and the elastic cylindrical portion 5c is formed in an arcuate shape 4 has an inner diameter equal to the outer diameter of 4 and a thickness smaller than the height of the wall 4a of the recess 4 and is integrally formed on both sides of the elastic tubular portion 5c; A connecting portion for a coaxial tube, characterized in that it is composed of a portion 5c and a split 5b formed continuously in the axial direction over the ring-shaped end portion 5a.